Freight, box, rail cars and the like are used to transport items across distances which vary in environment and topography. The doors on rail cars are generally mounted on rails which allow a door to slide horizontally to allow access to the inside of the rail car or to restrict access to the inside of the rail car. These doors are relatively large in stature and are made of metal since the loads carried within the rail cars can be large so the doors must be able to accept large items. The doors must also be durable due to the movement of the items within the rail car during transportation and due to the conditions surrounding the rail car during transportation. The conditions can consist of the elements such as rain, snow, wind and other weather conditions which can damage the items, and the conditions can consist of animals such as rodents entering the rail car which also can damage the items. A rail car door must also be able to be locked so that the items within the car are protected from theft and the like.
Some examples of doors of this type are found in U.S. Pat. No. 3,978,618 (Malo), U.S. Pat. No. 4,114,935 (Malo), U.S. Pat. No. 4,608,777 (Okamoto), U.S. Pat. No. 4,751,793 (Jenkins et al), U.S. Pat. No. 3,788,007 (Bailey), U.S. Pat. No. 4,091,570 (Favrel) and U.S. Pat. No. 5,142,823 (Brandenburg et al) which in general disclose a sliding door or the like arranged to enclose an area such as a rail car, each door being relatively unique in design but each does not adequately enclose the rail car door or the like. The doors do not seem to create a seal about an entrance so that water or the like may not enter, so that if a load such as paper is being hauled within the car, it is not protected and could be damaged. The doors have a locking device for locking the door either to close or to open an entrance.
Some examples of locking devices are shown in U.S. Pat. No. 4,852,918 (Allen), U.S. Pat. No. 4,763,385 (Furch et al), U.S. Pat. No. 3,820,283 (Acerra et al), U.S. Pat. No. 4,776,619 (Daugherty et al), U.S. Pat. No. 4,296,956 (Colombo) U.S. Pat. No. 5,056,835 (Johnson) and U.S. Pat. No. 5,302,072 (Stauffer et al).
There is a need for a rail car door which is creates a seal about the entrance, creating a complete seal by around such a large area by a large door is difficult. A door needs to be designed to ride on rails, as generally known, and needs to be able to be moved a relatively large distance inward by a relatively small force to create a seal on at the entrance.